Systems and methods for secure wireless transmission of power using unidirectional communication signals from a wireless-power-receiving device

ABSTRACT

An exemplary embodiment of secure wireless transmission of power using unidirectional communication signals from a wireless-power-receiving device. The method includes, receiving, from a wireless-power-transmitting device that includes a first communications radio, a first wireless-power-transmission signal at a wireless-power-receiving device that includes a second communications radio. In response to receiving the first wireless-power-transmission signal: broadcasting, via the second communications radio of the wireless-power-receiving device and without establishing a communications channel between the first and second communications radios, a data packet, the data packet including information identifying (i) at least one power requirement of a power source of the wireless-power-receiving device (ii) an amount of power received by the wireless-power-receiving device from the first wireless-power-transmission signal. After broadcasting the data packet, receiving, from the wireless-power-transmitting device, additional wireless-power-transmission signals at the wireless-power-receiving device, wherein the wireless-power-transmitting device transmits each of the additional wireless-power-transmission signals using a predetermined sequence of different transmission characteristics.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/385,755, filed on Jul. 26, 2021, entitled “Systems And Methods ForSecure Wireless Transmission Of Power Using Unidirectional CommunicationSignals From A Wireless-Power-Receiving Device,” which claims priorityto U.S. Provisional Application Ser. No. 63/178,465, filed Apr. 22,2021, entitled “Systems and Methods for Secure Wireless Transmission ofPower Using Unidirectional Communication Signals from AWireless-Power-Receiving Device,” and also claims priority from U.S.Provisional Application Ser. No. 63/064,912, filed Aug. 12, 2020,entitled “Systems and Methods for Secure Wireless Transmission of PowerUsing Unidirectional Communication Signals from AWireless-Power-Receiving Device,” both of which are incorporated by thisreference herein in their respective entireties.

TECHNICAL FIELD

The embodiments herein generally relate to systems and methods forwireless power transmission and, more specifically, to systems andmethods for secure wireless transmission of power using unidirectionalcommunication signals from a wireless-power-receiving device.

BACKGROUND

Some wireless power transmission systems, such as charging pads, utilizebidirectional communication between a wireless power receiving deviceand a wireless power transmitting device (e.g., a charging pad). Thesecharging pads (e.g., wireless power transmitting devices) have tocommunicate with wireless-power-receiving devices to ensure that thedevice to be charged is the correct device, and to receive charginginformation (e.g., battery level, charge state, power needed, etc.).Bidirectional communication frameworks can take up a lot of storagespace on the limited memory available on certain circuits used inconjunction with the reception of wireless power. Since storage is at apremium on these circuits, bidirectional communication can beundesirable, so there is a need for a communication framework that takesup less space, while still ensuring that power can be wirelesslytransmitted in a secure way.

SUMMARY

Accordingly, there is a need for a communication framework implementedat a wireless-power-receiving device (e.g., a device that includes (i)wireless-power-receiving circuitry, including at least one antenna andpower-conversion circuitry for converting wirelessly-delivered energyinto usable power and (ii) an electronic device, such as a smartphone,smart watch, laptop, hearing aid, that is configured to be powered orcharged by the usable power from the wireless-power-receiving circuitry)that uses minimal storage space. To this end, systems and methods aredescribed herein that are capable of allowing wireless-power-receivingdevices to receive a charge without establishing a communication channel(e.g., no handshake protocol is exchanged between a communication radioof a receiving device and a communication radio of a transmittingdevice). Instead of a bidirectional communication channel being used tocommunicate information related to wireless charging (e.g., radiofrequency power waves delivered over a distance towireless-power-receiving circuitry that then converts energy from the RFpower waves to usable power for charging or powering an electronicdevice coupled with the wireless-power-receiving device), unidirectionaladvertisements can be used to achieve desired results of a securetransmission of wireless power. In this improved communicationframework, the wireless-power-receiving device is able to transmitadvertisements, and a nearby wireless-power-transmitting device is ableto receive information that allows it to determine and adjust to thecharging needs of the wireless-power-receiving device based on dataincluded in these advertisements. Then the wireless-power-transmittingdevice provides a wirelessly-delivered charge to thewireless-power-receiving device. In some embodiments using thisframework, there is no communication received at thewireless-power-receiving device from the wireless-power-transmittingdevice. Thus, the wireless-power-receiving circuitry can be coupled withmany different types of electronic devices (e.g., smartphones, smartwatches, laptops, hearing aids, etc.) to allow those electronic devicesto be wirelessly charged using this unidirectional communicationframework and those electronic devices do not need additional softwareto allow them to receive a wireless charge. In other words, this newframework is advantageous over a bidirectional communication frameworkbecause it can be implemented using less storage space on thewireless-power-receiving device (while also not requiring anyadditional, or a very minimal amount of, storage space on an electronicdevice that is coupled with the wireless-power-receiving circuitry)without sacrificing security.

Note that the various embodiments described above can be combined withany other embodiments described herein. The features and advantagesdescribed in the specification are not all inclusive and, in particular,many additional features and advantages will be apparent to one ofordinary skill in the art in view of the drawings, specification, andclaims. Moreover, it should be noted that the language used in thespecification has been principally selected for readability andinstructional purposes, and not intended to circumscribe or limit theinventive subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the present disclosure can be understood in greater detail, amore particular description may be had by reference to the features ofvarious embodiments, some of which are illustrated in the appendeddrawings. The appended drawings, however, merely illustrate pertinentfeatures of the present disclosure and are therefore not to beconsidered limiting, for the description may admit to other effectivefeatures.

FIG. 1A is a block diagram of an RF wireless power transmission system,in accordance with some embodiments.

FIG. 1B is another block diagram of an RF wireless power transmissionsystem, in accordance with some embodiments.

FIG. 1C is a block diagram showing components of an example RF chargingpad that includes an RF power transmitter integrated circuit and antennazones, in accordance with some embodiments.

FIG. 1D is a block diagram showing components of an example RF chargingpad that includes an RF power transmitter integrated circuit coupled toa switch, in accordance with some embodiments.

FIG. 2 is a block diagram showing components of an example RFtransmitter, in accordance with some embodiments.

FIG. 3 is a block diagram showing components of an example RF receiver,in accordance with some embodiments.

FIG. 4 is a schematic flow diagram illustrating secure wirelesstransmission of power using unidirectional communication signals from awireless-power-receiving device.

FIGS. 5A-5C show flow diagrams of a method of transmittingunidirectional communication signals, in accordance with someembodiments.

In accordance with common practice, the various features illustrated inthe drawings may not be drawn to scale. Accordingly, the dimensions ofthe various features may be arbitrarily expanded or reduced for clarity.In addition, some of the drawings may not depict all of the componentsof a given system, method or device. Finally, like reference numeralsmay be used to denote like features throughout the specification andfigures.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. In the following detaileddescription, numerous specific details are set forth in order to providea thorough understanding of the various described embodiments. However,it will be apparent to one of ordinary skill in the art that the variousdescribed embodiments may be practiced without these specific details.In other instances, well-known methods, procedures, components,circuits, and networks have not been described in detail so as not tounnecessarily obscure aspects of the embodiments.

FIG. 1A is a block diagram of components of wireless power transmissionenvironment 100, in accordance with some embodiments. Wireless powertransmission environment 100 includes, for example, transmitters 102(e.g., transmitters 102 a, 102 b . . . 102 n), and one or more receivers120 (e.g., receivers 120 a, 120 b . . . 120 n). In some embodiments,each respective wireless power transmission environment 100 includes anumber of receivers 120 (also referred to as wireless-power-receivingcircuitry), each of which is associated with a respective electronicdevice 122. In some instances, the transmitter 102 is referred to hereinas a “wireless-power-transmitting device” or a “wireless powertransmitter.” Additionally, in some instances, the receiver 120 and theelectronic device 122 a, when coupled together are collectively referredto herein as a “wireless-power-receiving device.”

An example transmitter 102 (e.g., transmitter 102 a) includes, forexample, one or more processor(s) 104, a memory 106, one or more antennaarrays 110, one or more communications components 112 (also referred toherein as a “wireless communications radio,” a “communications radio” orsimply a “radio”), and/or one or more transmitter sensors 114. In someembodiments, these components are interconnected by way of acommunications bus 107. References to these components of transmitters102 cover embodiments in which one or more of these components (andcombinations thereof) are included. The components are discussed infurther detail below with reference to FIG. 2 .

In some embodiments, a single processor 104 (e.g., processor 104 oftransmitter 102 a) executes software modules for controlling multipletransmitters 102 (e.g., transmitters 102 b . . . 102 n). In someembodiments, a single transmitter 102 (e.g., transmitter 102 a) includesmultiple processors 104, such as one or more transmitter processors(configured to, e.g., control transmission of signals 116 by antennaarray 110), one or more communications component processors (e.g., insome embodiments the communications component is configured to receivecommunications transmitted by a wireless-power-receiving device withoutopening a communication channel, for example this also can mean that nohandshake protocol is necessary to allow the transmitter and receivingdevices to communicate with one another during a wireless-chargingprocess (as described in more detail below in reference to FIGS. 4 and5A-5C) and/or one or more sensor processors (configured to, e.g.,control operation of transmitter sensor 114 and/or receive output fromtransmitter sensor 114).

The receiver 120 receives power transmission signals 116. In someembodiments, the receiver 120 includes one or more antennas 124 (e.g.,an antenna array including multiple antenna elements), power converter126, receiver sensor 128, and/or other components or circuitry (e.g.,processor(s) 140, memory 142, and/or communication component(s) 144. Insome embodiments, these components are interconnected by way of acommunications bus 146. References to these components of receiver 120cover embodiments in which one or more of these components (andcombinations thereof) are included.

The receiver 120 converts energy from received signals 116 (alsoreferred to herein as RF power transmission signals, or simply, RFsignals, RF waves, power waves, or power transmission signals) intoelectrical energy to power and/or charge electronic device 122. Forexample, the receiver 120 uses the power converter 126 to convert energyderived from power waves 116 to alternating current (AC) electricity ordirect current (DC) electricity to power and/or charge the electronicdevice 122. Non-limiting examples of the power converter 126 includerectifiers, rectifying circuits, voltage conditioners, among suitablecircuitry and devices.

In some embodiments, the receiver 120 is a standalone device that isdetachably coupled to one or more electronic devices 122. For example,the electronic device 122 has processor(s) 132 for controlling one ormore functions of the electronic device 122, and the receiver 120 hasprocessor(s) 140 for controlling one or more functions of the receiver120.

In some embodiments, the receiver 120 is a component of the electronicdevice 122. For example, processors 132 control functions of theelectronic device 122 and the receiver 120. In addition, in someembodiments, the receiver 120 includes one or more processors 140, whichcommunicates with processors 132 of the electronic device 122.

In some embodiments, the electronic device 122 includes one or moreprocessors 132, memory 134, one or more communication components 136,and/or one or more batteries 130. In some embodiments, these componentsare interconnected by way of a communications bus 138. In someembodiments, communications between electronic device 122 and receiver120 occur via communications component(s) 136 and/or 144. In someembodiments, communications between the electronic device 122 and thereceiver 120 occur via a wired connection between communications bus 138and communications bus 146. In some embodiments, the electronic device122 and the receiver 120 share a single communications bus.

In some embodiments, the receiver 120 receives one or more power waves116 directly from the transmitter 102 (e.g., via one or more antennas124). In some embodiments, the receiver 120 harvests power waves fromone or more pockets of energy created by one or more power waves 116transmitted by the transmitter 102. In some embodiments, the transmitter102 is a near-field transmitter that transmits the one or more powerwaves 116 within a near-field distance (e.g., less than approximatelysix inches away from the transmitter 102, or in some other examples,less than (approximately) twelve inches away from the transmitter 102).In other embodiments, the transmitter 102 is a far-field transmitterthat transmits the one or more power waves 116 within a far-fielddistance (e.g., more than approximately six inches away from thetransmitter 102, or in some other examples more than (approximately)twelve inches away from the transmitter 102).

After the power waves 116 are received and/or energy is harvested fromthem, circuitry (e.g., integrated circuits, amplifiers, rectifiers,and/or voltage conditioner) of the receiver 120 converts the energy ofthe power waves to usable power (i.e., electricity), which powers theelectronic device 122 and/or is stored to battery 130 of the electronicdevice 122. In some embodiments, a rectifying circuit of the receiver120 translates the electrical energy from AC to DC for use by theelectronic device 122. In some embodiments, a voltage conditioningcircuit increases or decreases the voltage of the electrical energy asrequired by the electronic device 122. In some embodiments, anelectrical relay conveys electrical energy from the receiver 120 to theelectronic device 122.

In some embodiments, the electronic device 122 obtains power frommultiple transmitters 102 and/or using multiple receivers 120. In someembodiments, the wireless power transmission environment 100 includes aplurality of electronic devices 122, each having at least one respectivereceiver 120 that is used to harvest power waves from the transmitters102 into power for charging the electronic devices 122.

In some embodiments, the one or more transmitters 102 adjust values ofone or more characteristics (e.g., waveform characteristics, such asphase, gain, direction, amplitude, polarization, and/or frequency) ofpower waves 116. For example, a transmitter 102 selects a subset of oneor more antenna elements of antenna array 110 to initiate transmissionof power waves 116, cease transmission of power waves 116, and/or adjustvalues of one or more characteristics used to transmit power waves 116.In some embodiments, the one or more transmitters 102 adjust power waves116 such that trajectories of power waves 116 converge at apredetermined location within a transmission field (e.g., a location orregion in space), resulting in controlled constructive or destructiveinterference patterns. The transmitter 102 may adjust values of one ormore characteristics for transmitting the power waves 116 to account forchanges at the wireless power receiver that may negatively impacttransmission of the power waves 116. As described in more detail below,the adjustments made by the transmitter can be determined based on dataprovided in unidirectional communication signals from thewireless-power-receiving device (e.g., in which the communicationcomponent 136 of the device 122 a can be used to advertise data relatedto the receipt of RF power waves by the receiver 120, as described inmore detail below in reference to FIGS. 4 and 5A-5C).

Note that, in some embodiments, the transmitter 102 utilizes beamformingtechniques to wirelessly transfer power to a receiver 120, while inother embodiments, the transmitter 102 does not utilize beamformingtechniques to wirelessly transfer power to a receiver 120 (e.g., incircumstances in which no beamforming techniques are used, thetransmitter controller IC 160 discussed below might be designed withoutany circuitry to allow for use of beamforming techniques, or thatcircuitry may be present, but might be deactivated to eliminate anybeamforming control capability).

In some embodiments, respective antenna arrays 110 of the one or moretransmitters 102 may include a set of one or more antennas configured totransmit the power waves 116 into respective transmission fields of theone or more transmitters 102. Integrated circuits (FIG. 1C) of therespective transmitter 102, such as a controller circuit (e.g., a radiofrequency integrated circuit (RFIC)) and/or waveform generator, maycontrol the behavior of the antennas. For example, based on theinformation received from the receiver 120 by way of the communicationsignal 118 (e.g., an advertisement such as a Bluetooth Low Energy (BLE)advertisement), a controller circuit (e.g., processor 104 of thetransmitter 102, FIG. 1A) may determine values of the waveformcharacteristics (e.g., amplitude, frequency, trajectory, direction,phase, polarization, among other characteristics) of power waves 116that would effectively provide power to the receiver 120, and in turn,the electronic device 122. The controller circuit may also identify asubset of antennas from the antenna arrays 110 that would be effectivein transmitting the power waves 116. In some embodiments, a waveformgenerator circuit (not shown in FIG. 1A) of the respective transmitter102 coupled to the processor 104 may convert energy and generate thepower waves 116 having the specific values for the waveformcharacteristics identified by the processor 104/controller circuit, andthen provide the power waves to the antenna arrays 110 for transmission.

In some embodiments, the communications component 112 transmitscommunication signals 118 by way of a wired and/or wirelesscommunication connection to the receiver 120. In some embodiments, thecommunications component 112 does not transmit anything to the receiver120, and merely uses the communication component 112 to receivecommunications (e.g., BLE advertisements) from the receiver 120. In someembodiments, when the communications component 112 does not transmitanything to the receiver 120 there is no established communicationchannel between the communications component 112 and the receiver 120,which in some embodiments means that the receiving and transmittingdevices do not need to go through a handshake protocol to allow for thereceiving device to send BLE advertisements to the transmitting device.In some embodiments, the communications component 112 generates beaconsignals 118 a used for triangulation of the receiver 120 (e.g., testsignals). In some embodiments, the beacon signals 118 a are used toconvey information regarding charging availability from the transmitter102 to the receiver 120. In some embodiments, the signals 118 a are usedfor adjusting values of one or more waveform characteristics used totransmit the power waves 116 (e.g., convey amounts of power derived fromRF test signals). In some embodiments, the transmitter 102 does not needto convey information to the receiver 120 about adjusting values of oneor more waveform characteristics to transmit power waves 116, becausethe advertisements transmitted from the receiver convey all necessaryinformation to allow the transmitter 102 to provide power to thereceiver. In some embodiments, the beacon signals 118 a includeinformation related to status, efficiency, user data, power consumption,billing, geo-location, and other types of information (as is describedin more detail below). In some embodiments, unidirectional advertisementsignals 118 b are used to convey information regarding chargingrequirements from the receiver 120 to the transmitter 102. In someembodiments, only the unidirectional advertisement signals 118 btransmitted from the receiver 120 to the transmitter 102 includeinformation related to status, efficiency, user data, power consumption,charging information, billing, geo-location, and other types ofinformation.

In some embodiments, the communications component 112 includes acommunications component antenna for communicating with the receiver 120and/or other transmitters 102 (e.g., transmitters 102 b through 102 n).In some embodiments, these beacon signals 118 a unidirectionaladvertisement signals 118 b are sent using a first channel (e.g., afirst frequency band) that is independent and distinct from a secondchannel (e.g., a second frequency band distinct from the first frequencyband) used for transmission of the power waves 116. In some embodiments,no channel is created between the transmitter 102 and the receiver 120,and the communications component 112 receives incoming advertisements(e.g., BLE advertisements).

In some embodiments, the receiver 120 optionally includes areceiver-side communications component 144 (which can also be referredto herein as a second communications radio, while the communicationscomponent 112 can be referred to herein as a first communications radio)configured to communicate various types of data with one or more of thetransmitters 102, through a respective communication signal generated bythe receiver-side communications component (in some embodiments, arespective communication signal is referred to as an advertising oradvertisement signal). In other embodiments, the receiver 120 can beconfigured to use the communications component 136 of the device 122 afor the purpose of communicating the unidirectional communicationadvertisements discussed herein (the descriptions herein of theunidirectional advertisements apply to circumstances in which thereceiver 120 uses its own communications component 144, as well as tocircumstances in which the receiver 120 uses the communicationscomponent 136 of the device 122 a). The data may include locationindicators for the receiver 120 and/or electronic device 122, a powerstatus of the device 122, status information for the receiver 120,status information for the electronic device 122 (e.g., not charging,charging but needs more power, charging at optimal configured rate,charging but receiving too much power, any fault condition, etc.),status information about the power waves 116 (e.g., whether theelectronic device 122 requires charging, battery is critical, whetherthe receiver is on the charger (e.g., transmitter 102) or not (arrayvoltage detected), etc.), and/or status information for pockets ofenergy. In other words, the receiver 120 may provide data to thetransmitter 102, by way of the beacon signals 118 a and/orunidirectional advertisement signals 118 b regarding the currentoperation of the system 100, including: information identifying apresent location of the receiver 120 or the device 122, an amount ofenergy (i.e., usable power) received by the receiver 120, and an amountof power received and/or used by the electronic device 122, among otherpossible data points containing other types of information.

In some embodiments, the data contained within beacon signals 118 aand/or unidirectional advertisement signals 118 b is used by theelectronic device 122, the receiver 120, and/or the transmitters 102 fordetermining adjustments to values of one or more waveformcharacteristics used by the antenna array 110 to transmit the powerwaves 116. In some embodiments, the receiver 120 uses a beacon signals118 a and/or unidirectional advertisement signals 118 b to communicatedata for, e.g., alerting transmitters 102 that the receiver 120 hasentered or is about to enter a transmission field (e.g., come withinwireless-power-transmission range of a transmitter 102), provideinformation about the electronic device 122, provide user informationthat corresponds to the electronic device 122, indicate theeffectiveness of received power waves 116, and/or provide updatedcharacteristics or transmission parameters that the one or moretransmitters 102 use to adjust transmission of the power waves 116. Insome embodiments, the alerting of transmitters occurs in response to theelectronic device 122 detecting a transmitter beacon signal produced bythe transmitter 102. In some embodiments, the transmitter beacon signalis a low-power RF signal, such that the transmitter beacon signal has alower power level relative to additional wireless-power-transmissionsignals that are transmitted subsequently after the transmitter hasdetermined that the receiver is within a wireless-power-transmissionrange of the transmitter (an example of this is shown in the flowchartof FIG. 4 ).

In some embodiments, transmitter sensor 114 and/or receiver sensor 128detect and/or identify conditions of the electronic device 122, thereceiver 120, the transmitter 102, and/or a transmission field. In someembodiments, data generated by the transmitter sensor 114 and/orreceiver sensor 128 is used by the transmitter 102 to determineappropriate adjustments to values of one or more waveformcharacteristics used to transmit the power waves 116. Data fromtransmitter sensor 114 and/or receiver sensor 128 received by thetransmitter 102 includes, for example, raw sensor data and/or sensordata processed by a processor 104, such as a sensor processor. Processedsensor data includes, for example, determinations based upon sensor dataoutput. In some embodiments, sensor data received from sensors that areexternal to the receiver 120 and the transmitters 102 is also used (suchas thermal imaging data, information from optical sensors, and others).

FIG. 1B is another block diagram of an RF wireless power transmissionsystem 150 in accordance with some embodiments. In some embodiments, theRF wireless power transmission system 150 includes a far-fieldtransmitter (not shown). In some embodiments, the RF wireless powertransmission system 150 includes a near-field transmitter that, in someembodiments, can be part of an RF charging pad 151 (also referred toherein as a near-field (NF) charging pad 151 or RF charging pad 151).The RF charging pad 151 may be an example of the transmitter 102 in FIG.1A.

In some embodiments, the RF charging pad 151 includes an RF powertransmitter integrated circuit 160 (described in more detail below). Insome embodiments, the RF charging pad 151 includes one or morecommunications components 112 (e.g., wireless communication components,such as WI-FI or BLUETOOTH radios). In some embodiments, the RF chargingpad 151 also connects to one or more power amplifier units 108-1, . . .108-n (PA or PA units) to control operation of the one or more poweramplifier units when they drive external power-transfer elements (e.g.,antennas 290). In some embodiments, RF power is controlled and modulatedat the RF charging pad 151 via switch circuitry as to enable the RFwireless power transmission system to send RF power to one or morewireless receiving devices via the TX antenna array 110.

FIG. 1C is a block diagram of the RF power transmitter integratedcircuit 160 (the “integrated circuit”) in accordance with someembodiments. In some embodiments, the integrated circuit 160 includes aCPU subsystem 170, an external device control interface, an RFsubsection for DC to RF power conversion, and analog and digital controlinterfaces interconnected via an interconnection component, such as abus or interconnection fabric block 171. In some embodiments, the CPUsubsystem 170 includes a microprocessor unit (CPU) 202 with relatedRead-Only-Memory (ROM) 172 for device program booting via a digitalcontrol interface, e.g., an I²C port, to an external FLASH containingthe CPU executable code to be loaded into the CPU Subsystem RandomAccess Memory (RAM) 174 (e.g., memory 206, FIG. 2A) or executed directlyfrom FLASH. In some embodiments, the CPU subsystem 170 also includes anencryption module or block 176 to authenticate and secure communicationexchanges with external devices, such as wireless power receivers thatattempt to receive wirelessly delivered power from the RF charging pad150.

In some embodiments, the RF IC 160 also includes (or is in communicationwith) a power amplifier controller IC 161A (PA IC) that is responsiblefor controlling and managing operations of a power amplifier (ormultiple power amplifiers), including for reading measurements ofimpedance at various measurement points within the power amplifier 108,whereby these measurements are used, in some instances, for detecting offoreign objects. The PA IC 161A may be on the same integrated circuit atthe RF IC 160, or may be on its on integrated circuit that is separatefrom (but still in communication with) the RF IC 160. Additional detailsregarding the architecture and operation of the PA IC are provided inU.S. Provisional Patent Application No. 62/03,677 (Attorney Docket No.117685-5197-PR), the disclosure of which is incorporated by referenceherein in its entirety.

In some embodiments, executable instructions running on the CPU (such asthose shown in the memory 106 in FIG. 2 and described below) are used tomanage operation of the RF charging pad 151 and to control externaldevices through a control interface, e.g., SPI control interface 175,and the other analog and digital interfaces included in the RF powertransmitter integrated circuit 160. In some embodiments, the CPUsubsystem also manages operation of the RF subsection of the RF powertransmitter integrated circuit 160, which includes an RF localoscillator (LO) 177 and an RF transmitter (TX) 178. In some embodiments,the RF LO 177 is adjusted based on instructions from the CPU subsystem170 and is thereby set to different desired frequencies of operation,while the RF TX converts, amplifies, modulates the RF output as desiredto generate a viable RF power level.

In the descriptions that follow, various references are made to antennazones and power-transfer zones, which terms are used synonymously inthis disclosure. In some embodiments the antenna/power-transfer zonesmay include antenna elements that transmit propagating radio frequencywaves but, in other embodiments, the antenna/power transfer zones mayinstead include capacitive charging couplers that convey electricalsignals but do not send propagating radio frequency waves.

In some embodiments, the RF power transmitter integrated circuit 160provides the viable RF power level (e.g., via the RF TX 178) to anoptional beamforming integrated circuit (IC) 109, which then providesphase-shifted signals to one or more power amplifiers 108. In someembodiments, the beamforming IC 109 is used to ensure that powertransmission signals sent using two or more antennas 210 (e.g., eachantenna 210 may be associated with a different antenna zone 290 or mayeach belong to a single antenna zone 290) to a particular wireless powerreceiver are transmitted with appropriate characteristics (e.g., phases)to ensure that power transmitted to the particular wireless powerreceiver is maximized (e.g., the power transmission signals arrive inphase at the particular wireless power receiver). In some embodiments,the beamforming IC 109 forms part of the RF power transmitter IC 160. Inembodiments in which capacitive couplers (e.g., capacitive chargingcouplers 244) are used as the antennas 210, then optional beamforming IC109 may not be included in the RF power transmitter integrated circuit160.

In some embodiments, the RF power transmitter integrated circuit 160provides the viable RF power level (e.g., via the RF TX 178) directly tothe one or more power amplifiers 108 and does not use the beamforming IC109 (or bypasses the beamforming IC if phase-shifting is not required,such as when only a single antenna 210 is used to transmit powertransmission signals to a wireless power receiver). In some embodiments,the PA IC 161A receives the viable RF power level and provides that tothe one or more power amplifiers 108.

In some embodiments, the one or more power amplifiers 108 then provideRF signals to the antenna zones 290 (also referred to herein as“power-transfer zones”) for transmission to wireless power receiversthat are authorized to receive wirelessly delivered power from the RFcharging pad 151. In some embodiments, each antenna zone 290 is coupledwith a respective PA 108 (e.g., antenna zone 290-1 is coupled with PA108-1 and antenna zone 290-N is coupled with PA 108-N). In someembodiments, multiple antenna zones are each coupled with a same set ofPAs 108 (e.g., all PAs 108 are coupled with each antenna zone 290).Various arrangements and couplings of PAs 108 to antenna zones 290 allowthe RF charging pad 151 to sequentially or selectively activatedifferent antenna zones in order to determine the most efficient antennazone 290 to use for transmitting wireless power to a wireless powerreceiver. In some embodiments, the one or more power amplifiers 108 arealso in communication with the CPU subsystem 170 to allow the CPU 202 tomeasure output power provided by the PAs 108 to the antenna zones 110 ofthe RF charging pad 151.

FIG. 1C also shows that, in some embodiments, the antenna zones 290 ofthe RF charging pad 151 may include one or more antennas 210A-N. In someembodiments, each antenna zone of the plurality of antenna zones 290includes one or more antennas 210 (e.g., antenna zone 290-1 includes oneantenna 210-A and antenna zones 290-N includes multiple antennas 210).In some embodiments, a number of antennas included in each of theantenna zones is dynamically defined based on various parameters, suchas a location of a wireless power receiver on the RF charging pad 151.In some embodiments, each antenna zone 290 may include antennas ofdifferent types, while in other embodiments each antenna zone 290 mayinclude a single antenna of a same type, while in still otherembodiments, the antennas zones may include some antenna zones thatinclude a single antenna of a same type and some antenna zones thatinclude antennas of different types. In some embodiments theantenna/power-transfer zones may also or alternatively includecapacitive charging couplers that convey electrical signals but do notsend propagating radio frequency waves.

In some embodiments, the RF charging pad 151 may also include atemperature monitoring circuit that is in communication with the CPUsubsystem 170 to ensure that the RF charging pad 151 remains within anacceptable temperature range. For example, if a determination is madethat the RF charging pad 151 has reached a threshold temperature, thenoperation of the RF charging pad 151 may be temporarily suspended untilthe RF charging pad 151 falls below the threshold temperature.

By including the components shown for RF power transmitter circuit 160(FIG. 1C) on a single chip, such transmitter chips are able to manageoperations at the transmitter chips more efficiently and quickly (andwith lower latency), thereby helping to improve user satisfaction withthe charging pads that are managed by these transmitter chips. Forexample, the RF power transmitter circuit 160 is cheaper to construct,has a smaller physical footprint, and is simpler to install.

FIG. 1D is a block diagram of a charging pad 294 in accordance with someembodiments. The charging pad 294 is an example of the charging pad 151(FIG. 1B), however, one or more components included in the charging pad151 are not included in the charging pad 294 for ease of discussion andillustration.

The charging pad 294 includes an RF power transmitter integrated circuit160, one or more power amplifiers 108, a PA IC 161A (which may be on thesame or a separate IC from the RF power transmitter IC 160), and atransmitter antenna array 290 having multiple antenna zones. Each ofthese components is described in detail above with reference to FIGS.1A-1C. Additionally, the charging pad 294 includes a switch 295 (i.e.,transmitter-side switch), positioned between the power amplifiers 108and the antenna array 290, having a plurality of switches 297-A, 297-B,. . . 297-N. The switch 295 is configured to switchably connect one ormore power amplifiers 108 with one or more antenna zones of the antennaarray 290 in response to control signals provided by the RF powertransmitter integrated circuit 160.

To accomplish the above, each switch 297 is coupled with (e.g., providesa signal pathway to) a different antenna zone of the antenna array 290.For example, switch 297-A may be coupled with a first antenna zone 290-1(FIG. 1C) of the antenna array 290, switch 297-B may be coupled with asecond antenna zone 290-2 of the antenna array 290, and so on. Each ofthe plurality of switches 297-A, 297-B, . . . 297-N, once closed,creates a unique pathway between a respective power amplifier 108 (ormultiple power amplifiers 108) and a respective antenna zone of theantenna array 290. Each unique pathway through the switch 295 is used toselectively provide RF signals to specific antenna zones of the antennaarray 290. It is noted that two or more of the plurality of switches297-A, 297-B, . . . 297-N may be closed at the same time, therebycreating multiple unique pathways to the antenna array 290 that may beused simultaneously.

In some embodiments, the RF power transmitter integrated circuit 160 (orthe PA IC 161A, or both) is (are) coupled to the switch 295 and isconfigured to control operation of the plurality of switches 297-A,297-B, . . . 297-N(illustrated as a “control out” signal in FIGS. 1B and1D). For example, the RF power transmitter integrated circuit 160 mayclose a first switch 297-A while keeping the other switches open. Inanother example, the RF power transmitter integrated circuit 160 mayclose a first switch 297-A and a second switch 297-B, and keep the otherswitches open (various other combinations and configuration arepossible). Moreover, the RF power transmitter integrated circuit 160 iscoupled to the one or more power amplifiers 108 and is configured togenerate a suitable RF signal (e.g., the “RF Out” signal) and providethe RF signal to the one or more power amplifiers 108. The one or morepower amplifiers 108, in turn, are configured to provide the RF signalto one or more antenna zones of the antenna array 290 via the switch295, depending on which switches 297 in the switch 295 are closed by theRF power transmitter integrated circuit 160.

In some embodiments, the charging pad is configured to transmit testpower transmission signals and/or regular power transmission signalsusing different antenna zones, e.g., depending on a location of areceiver on the charging pad. Accordingly, when a particular antennazone is selected for transmitting test signals or regular power signals,a control signal is sent to the switch 295 from the RF power transmitterintegrated circuit 160 to cause at least one switch 297 to close. Indoing so, an RF signal from at least one power amplifier 108 can beprovided to the particular antenna zone using a unique pathway createdby the now-closed at least one switch 297.

In some embodiments, the switch 295 may be part of (e.g., internal to)the antenna array 290. Alternatively, in some embodiments, the switch295 is separate from the antenna array 290 (e.g., the switch 295 may bea distinct component, or may be part of another component, such as thepower amplifier(s) 108). It is noted that any switch design capable ofaccomplishing the above may be used, and the design of the switch 295illustrated in FIG. 1D is merely one example.

FIG. 2 is a block diagram illustrating a representative transmitterdevice 102 (also sometimes referred to herein as a transmitter 102, awireless power transmitter 102, and a wireless-power-transmitting device102) in accordance with some embodiments. In some embodiments, thetransmitter device 102 includes one or more processors 104 (e.g., CPUs,ASICs, FPGAs, microprocessors, and the like), one or more communicationcomponents 112 (e.g., radios), memory 106, one or more antennas 110, andone or more communication buses 108 for interconnecting these components(sometimes called a chipset). In some embodiments, the transmitterdevice 102 includes one or more sensors 114 as described above withreference to FIG. 1A. In some embodiments, the transmitter device 102includes one or more output devices such as one or more indicatorlights, a sound card, a speaker, a small display for displaying textualinformation and error codes, etc. In some embodiments, the transmitterdevice 102 includes a location detection device, such as a GPS (globalpositioning satellite) or other geo-location receiver, for determiningthe location of the transmitter device 102.

The communication components 112 enable communication between thetransmitter 102 and the receiver 120 (e.g., one or more communicationnetworks). In some embodiments, the communication components 112include, e.g., hardware capable of data communications using any of avariety of wireless protocols (e.g., IEEE 802.15.4, Wi-Fi, ZigBee,6LoWPAN, Thread, Z-Wave, Bluetooth Smart, ISA100.11a, WirelessHART,MiWi, etc.) wired protocols (e.g., Ethernet, HomePlug, etc.), and/or anyother suitable communication protocol, including communication protocolsnot yet developed as of the filing date of this document.

The memory 106 includes high-speed random access memory, such as DRAM,SRAM, DDR SRAM, or other random access solid state memory devices; and,optionally, includes non-volatile memory, such as one or more magneticdisk storage devices, one or more optical disk storage devices, one ormore flash memory devices, or one or more other non-volatile solid statestorage devices. The memory 106, or alternatively the non-volatilememory within memory 106, includes a non-transitory computer-readablestorage medium. In some embodiments, the memory 106, or thenon-transitory computer-readable storage medium of the memory 106,stores the following programs, modules, and data structures, or a subsetor superset thereof:

-   -   operating logic 216 including procedures for handling various        basic system services and for performing hardware dependent        tasks;    -   communication module 218 for coupling to and/or communicating        with remote devices (e.g., remote sensors, transmitters,        receivers, servers, etc.), in conjunction with communication        component(s) 112 and/or antenna(s) 110;    -   sensor module 220 for obtaining and processing sensor data        (e.g., in conjunction with sensor(s) 114) to, for example,        determine the presence, velocity, and/or positioning of object        in the vicinity of the transmitter 102;    -   power wave generating module 224 for generating and transmitting        (e.g., in conjunction with antenna(s) 110) power waves. In some        embodiments, the power wave generating module 224 receives        instructions from the transmitter controller IC based on        information provided by unidirectional communication signals        received at the transmitter from the receiving device (an        example of which is shown in FIG. 4 );    -   database 226, including but not limited to:        -   sensor information 228 for storing and managing data            received, detected, and/or transmitted by one or more            sensors (e.g., sensors 114 and/or one or more remote            sensors);        -   communication protocol information 234 for storing and            managing protocol information for one or more protocols            (e.g., custom or standard wireless protocols, such as            ZigBee, Z-Wave, etc., and/or custom or standard wired            protocols, such as Ethernet).        -   unidirectional advertisement structure 237 allows the first            communications radio of the transmitting device to decipher            information provided by a second communications radio of a            receiving device in, e.g. a BLE advertisement signal.

Each of the above-identified elements (e.g., modules stored in memory106 of the transmitter 102) is optionally stored in one or more of thepreviously mentioned memory devices, and corresponds to a set ofinstructions for performing the function(s) described above. The aboveidentified modules or programs (e.g., sets of instructions) need not beimplemented as separate software programs, procedures, or modules, andthus various subsets of these modules are optionally combined orotherwise rearranged in various embodiments. In some embodiments, thememory 106, optionally, stores a subset of the modules and datastructures identified above. Furthermore, the memory 106, optionally,stores additional modules and data structures not described above, suchas a tracking module for tracking the movement and positioning ofobjects within a transmission field.

FIG. 3 is a block diagram illustrating a representative receiver device120 (also referred to herein as a receiver 120, a wireless powerreceiver 120, and wireless-power-receiving circuitry 120) in accordancewith some embodiments. In some embodiments, the receiver device 120includes one or more processors 140 (e.g., CPUs, ASICs, FPGAs,microprocessors, and the like), one or more communication components144, memory 142, one or more antennas 124, power harvesting circuitry310, and one or more communication buses 308 for interconnecting thesecomponents (sometimes called a chipset). In some embodiments, thereceiver device 120 includes one or more sensors 128 such as one orsensors described above with reference to FIG. 1A. In some embodiments,the receiver device 120 includes an energy storage device 312 forstoring energy harvested via the power harvesting circuitry 310. Invarious embodiments, the energy storage device 312 includes one or morebatteries (e.g., battery 130, FIG. 1A), one or more capacitors, one ormore inductors, and the like.

As described above with reference to FIG. 1A, in some embodiments, thereceiver 120 is internally or externally connected to an electronicdevice (e.g., electronic device 122 a, FIG. 1A) via a connection 138(e.g., a bus). In some embodiments, the energy storage device 312 ispart of the electronic device.

In some embodiments, the power harvesting circuitry 310 includes one ormore rectifying circuits and/or one or more power converters. In someembodiments, the power harvesting circuitry 310 includes one or morecomponents (e.g., a power converter 126) configured to convert energyfrom power waves and/or energy pockets to electrical energy (e.g.,electricity). In some embodiments, the power harvesting circuitry 310 isfurther configured to supply power to a coupled electronic device (e.g.,an electronic device 122), such as a laptop or phone. In someembodiments, supplying power to a coupled electronic device includetranslating electrical energy from an AC form to a DC form (e.g., usableby the electronic device 122).

The communication component(s) 144 enable communication between thereceiver 120 and the transmitter 102 (e.g., via one or morecommunication networks). In some embodiments, the communicationcomponent(s) 144 include, e.g., hardware capable of data communicationsusing any of a variety of custom or standard wireless protocols (e.g.,IEEE 802.15.4, Wi-Fi, ZigBee, 6LoWPAN, Thread, Z-Wave, Bluetooth Smart,ISA100.11a, WirelessHART, MiWi, etc.) custom or standard wired protocols(e.g., Ethernet, HomePlug, etc.), and/or any other suitablecommunication protocol, including communication protocols not yetdeveloped as of the filing date of this document. In some embodiments,the receiver 120 uses a communications component of the electronicdevice. In some embodiments, when the receiver 120 uses a communicationscomponent of the electronic device, the receiver 120 does not include acommunication component 144. In some embodiments, the communicationscomponent is external to the receiver 120.

The memory 142 includes high-speed random access memory, such as DRAM,SRAM, DDR SRAM, or other random access solid state memory devices; and,optionally, includes non-volatile memory, such as one or more magneticdisk storage devices, one or more optical disk storage devices, one ormore flash memory devices, or one or more other non-volatile solid statestorage devices. The memory 142, or alternatively the non-volatilememory within memory 142, includes a non-transitory computer-readablestorage medium. In some embodiments, the memory 142, or thenon-transitory computer-readable storage medium of the memory 142,stores the following programs, modules, and data structures, or a subsetor superset thereof:

-   -   operating logic 314 including procedures for handling various        basic system services and for performing hardware dependent        tasks;    -   communication module 316 for coupling to and/or communicating        with remote devices (e.g., remote sensors, transmitters, other        receivers, servers, electronic devices, mapping memories, etc.)        in conjunction with the communication component(s) 144 and/or        antenna(s) 124. For example, the communication module 316 can be        used in conjunction with second communications radio of the        receiving device to provide advertisement signals to a first        communications radio of the transmitting device, such that the        second communications radio is able to provide data packets to        the first communications radio that allow the transmitter to        make certain adjustment to the transmission of power to the        receiving device (and all this can be done without establishing        a communication channel between the first and second        communications radios);    -   sensor module 318 for obtaining and processing sensor data        (e.g., in conjunction with sensor(s) 128) to, for example,        determine the presence, velocity, and/or positioning of the        receiver 120, a transmitter 102, or an object in the vicinity of        the receiver 120;    -   power receiving module 320 for receiving (e.g., in conjunction        with antenna(s) 124 and/or power harvesting circuitry 310) and        optionally converting (e.g., in conjunction with power        harvesting circuitry 310) the energy (e.g., to direct current);        transferring the energy to a coupled electronic device (e.g., an        electronic device 122); and optionally storing the energy (e.g.,        in conjunction with energy storage device 312)    -   power determining module 321 for determining (in conjunction        with operation of the power receiving module 320) an amount of        power received by the receiver based on energy extracted from        power waves (or RF test signals) and/or pockets or energy at        which the power waves converge (e.g., RF signals 116, FIG. 1A).        In some embodiments, the amount of power is reported in the data        packets provided in the advertisement signals sent from the        second communications radio of the receiving device to the first        communications radio of the transmitting device;    -   a switch module 330 for signaling when to open a switch of the        power harvesting circuitry 310 in order to stop power surges        from damaging sensitive components;    -   A toggle module 332 for controlling the impedance mismatch in        the system, which in turn can cause a portion of the incoming        power to be reflected from the antenna of the wireless power        receiver. By modulating the amount of power reflected by the        antenna device can communicate with a wireless power transmitter        without needing a dedicate communication component (e.g., IEEE        802.15.4, Wi-Fi, ZigBee, 6LoWPAN, Thread, Z-Wave, Bluetooth        Smart, ISA100.11a, WirelessHART, MiWi, etc.) wired protocols        (e.g., Ethernet, HomePlug, etc.); and    -   database 322, including but not limited to:        -   sensor information 324 for storing and managing data            received, detected, and/or transmitted by one or more            sensors (e.g., sensors 128 and/or one or more remote            sensors);        -   device settings 326 for storing and managing operational            settings for the receiver 120, a coupled electronic device            (e.g., an electronic device 122), and/or one or more remote            devices; and        -   communication protocol information 328 for storing and            managing protocol information for one or more protocols            (e.g., custom or standard wireless protocols, such as            ZigBee, Z-Wave, etc., and/or custom or standard wired            protocols, such as Ethernet).        -   unidirectional advertisement structure 330 allows the first            communications radio of the transmitting device to decipher            information provided by a second communications radio of a            receiving device in, e.g. a BLE advertisement signal.

In some embodiments, the power receiving module 320 communicates theamount of power to the communication module 316, which communicates theamount of power to other remote devices (e.g., transmitter 102, FIGS.1-2 ). In some embodiments, this communication model 316 transmitsadvertisements, and does not open a dedicated channel with anyparticular transmitter (e.g., transmitter 102). Moreover, in someembodiments, the power receiving module 320 may communicate the amountof power to database 322 (e.g., the database 322 stores the amount ofpower derived from one or more power waves 116). Alternatively, in someembodiments, the power receiving module 320 instructs the communicationmodule 316 to transmit data packets to the remote devices (e.g., arespective data packet can include information for multiple test signalstransmitted by the transmitter 102).

In some embodiments, the wireless-power transmission system describedherein can be used in one or more of: near-field, NF+, mid-field, andfar-field transmission applications. Near-field refers to the regionaround the transmission antenna that is within approximately onewavelength or less (of a power wave to be transmitted by the transmitterdevice at a certain frequency). Far-field refers to the region aroundthe transmission antenna that is approximately two wavelengths or more(of a power wave to be transmitted by the transmitter device at acertain frequency). Mid-field refers to the region between near fieldand far field. For example, when the frequency of a transmission wave is2.4 GHz, the NF+ range is equal or within around 0.188 m, the near-fieldrange is equal or within around 0.125 m, the mid-field range is fromaround 0.125 m to around 0.25 m, and the far-field range is equal orgreater than around 0.25 m. In another example, when the frequency ofthe transmission wave is 5 GHz, the NF+ range is equal or within around0.09 m, the near-field range is equal or within around 0.06 m, themid-field range is from around 0.06 m to around 0.12 m, and thefar-field range is equal or greater than around 0.12 m. In someembodiments, the operating frequency ranges from 400 MHz to 60 GHz.

Each of the above identified elements (e.g., modules stored in memory142 of the receiver 120) is optionally stored in one or more of thepreviously mentioned memory devices, and corresponds to a set ofinstructions for performing the function(s) described above. The aboveidentified modules or programs (e.g., sets of instructions) need not beimplemented as separate software programs, procedures, or modules, andthus various subsets of these modules are optionally combined orotherwise rearranged in various embodiments. In some embodiments, thememory 142, optionally, stores a subset of the modules and datastructures identified above. Furthermore, the memory 142, optionally,stores additional modules and data structures not described above, suchas an identifying module for identifying a device type of a connecteddevice (e.g., a device type for an electronic device 122).

Simplex NF/NF+ Software Design Overview

In some embodiments, in a simplex mode the communication between awireless-power transmitting device (e.g., transmitter 402 in FIG. 4 ,equivalent to transmitter 102 in FIG. 1 ) and wireless-power receivingdevice (e.g., receiver 404 in FIG. 4 , equivalent to receiver 120 inFIG. 1 ) happens in one direction (e.g., unidirectional communication).In some embodiments, a Bluetooth Low Energy (BLE) advertisement (e.g.,indicated by BLE advertisement arrow 406 in FIG. 4 ) from a receiver 404is used by the transmitter 402 as a pseudo one-way communication channelto receive the advertisements. The following description describes thesystem requirements, operation/provisioning modes, design, andimplementation details of at least one embodiment.

Acronyms Used in the Descriptions Herein

AD Advertisement Data ADV Advertisement AFV Advertisement Format VersionAPI Application Programming Interface BLE Bluetooth Low Energy RXReceiver TX Transmitter RF Radio Frequency WPT Wireless Power Transfer

Advantages

Below is a summary of example advantages of the disclosed embodiments.In some embodiments, the secure wireless transmission of power usingunidirectional communication is advantageous because it is simpler toimplement for end customers. In some embodiments, the amount of softwarecode on the wireless-power receiving device is minimal. In someembodiments, wireless-power-transmitting device 402 is able to verifythat the wireless-power-receiving device 404 receives power based ononly the one-way communications it receives from thewireless-power-receiving device 404. The system also has the ability tocease sending power to a receiver that is already being sent power bynearby transmitters. In some embodiments, the wireless-power-transmitterincludes counter measures for combating unauthorized receivers ormitigating replay while receiving broadcasts from awireless-power-transmitting device.

In some embodiments, wireless-power-receiving device broadcasts, via BLEadvertisements, the below information corresponding to power, voltage,battery percentage, and charge status. In some embodiments, thewireless-power receiving device can broadcast, via BLE advertisements,whether a storage element (e.g., a battery, capacitor, etc.,) of thewireless-power-receiving device requires charging. In some embodiments,the wireless-power receiving device can broadcast, via BLEadvertisements, the condition of the storage element associated with thewireless-power-receiving device is in a critical state (e.g., not withinoperating temperature, overcharged, undercharged, or another errorassociated with storage elements). In some embodiments, thewireless-power receiving device can broadcast, via BLE advertisements,whether the wireless-power-receiving device is within range of thewireless-power-transmitter device or not (e.g., the array voltage isdetected). In some embodiments, the wireless-power receiving device canbroadcast, via BLE advertisements, that the storage element associatedwith the wireless-power-receiving device is not charging. In someembodiments, the wireless-power receiving device can broadcast, via BLEadvertisements, that the storage element associated with thewireless-power-receiving device is charging but needs more power fromthe wireless-power-transmitting device. In some embodiments, thewireless-power receiving device can broadcast, via BLE advertisements,that the storage element associated with the wireless-power-receivingdevice is charging at an optimal configured rate from thewireless-power-transmitting device. In some embodiments, thewireless-power receiving device can broadcast, via BLE advertisements,that the storage element associated with the wireless-power-receivingdevice is charging but is receiving too much power from thewireless-power-transmitting device. In some embodiments, thewireless-power receiving device can broadcast, via BLE advertisements,that the storage element and/or the wireless-power-receiving device ispresenting a fault condition.

System Communication Model

In some embodiments, the wireless-power-transmitting device 404 monitorsreceived wireless-power-transmission signals in accordance with thebroadcasted data packet (e.g., BLE advertisement broadcasted from thewireless-power-transmitting device 402). For example, FIG. 4 first showsarrow 406 that corresponds to a BLE advertisement, and then shows at alater time a change in received RF power, as indicated by arrow 408stating “RF Power”). In some embodiments, the wireless-power-receivingdevice 402 continuously updates its broadcasted data packets (e.g., BLEadvertisement data) with its current charging state of the storageelement associated with the wireless-power-receiving device 402, thevoltage, power received from the wireless-power-transmitting device 404,and whether more or less power is required from thewireless-power-transmitting device 404, etc. (e.g., as indicated by textbox 410 in FIG. 4 that recites that advertising occurs every 100 ms).

In some embodiments, the wireless-power-transmitting device 404 confirmsthe received broadcasted data packets (e.g., reporting) from thewireless-power-receiving device 402 is correct for the transmitter'sstate For example, in some embodiments, this is achieved by having thewireless-power-transmitting device 404 use a pattern (e.g., a randompattern) of turning the power ON and OFF the power emitted by thewireless-power-transmitting device 404 and determining, via thewireless-power-transmitting device, whether the wireless-power-receivingdevice's 402 broadcasted information that includes received powerinformation (e.g., the reporting values) corresponds to the powertransmitted by the wireless-power-transmitting device 404 (e.g., asindicated in FIG. 4 by the process block 412, which illustrates such aninteraction). This confirmation process ensures that thewireless-power-transmitting device 404 is tracking the correctwireless-power-receiving device(s) 402 even if other transmitters (e.g.,ones provided by manufacturer different from the transmitterimplementing the simplex communication method described herein) ischarging other wireless-power-receiving devices nearby. An illustrationof this interaction is shown in FIG. 4 .

In some embodiments, each of the additional wireless power-transmissionsignals (e.g., arrow 416 stating “RF Power” in FIG. 4 ) has a certainpower level that is both predetermined by thewireless-power-transmitting device 402 and is a higher power level thanthe power level that was used for a first wireless-power-transmissionsignal (e.g., arrow 408 stating “RF Power” in FIG. 4 ). In this way,receipt of the additional wireless-power-transmission signals at thewireless-power-receiving device 404 can be verified by thewireless-power-transmitting device 404 by checking a reported powerlevel from the wireless-power-receiving device 402 (e.g., arrow 416stating “RF Power” in FIG. 4 ).

System Supported Modes

In some embodiments, the system communication model is an open mode, andthere is no authentication and/or encryption in this mode. In someembodiments, the open mode can be useful for devices with very smallmemory footprints (e.g., 32 kBs) and charging requirements where dataprotection is not required.

In some embodiments, the system is protected, and data will be encryptedusing shared key. For example, in some embodiments at least someportions of the data included in the broadcasted data packets (e.g., BLEadvertisements and/or WPT beacon) will be encrypted using a shared key.This mode provides a level of security without taking up much memoryspace. The shared key can be protected to avoid potential securitythreats, and the shared key in some embodiments can be provisioned atthe manufacturing time.

In some embodiments, the system is private, and authentication andencryption are provided using public key cryptography. For example, insome embodiments at least some portions of the data included in thebroadcasted data packets (e.g., BLE advertisements and/or WPT beacon)will be encrypted using a public key. In some embodiments,wireless-power-receiving device 402 and wireless-power transmittingdevice 404 can be provisioned using the public key of another party toderive a common pre-shared key. This key can be directly or indirectlyused to encrypt the data found within the broadcast. This security modeprovides additional security compared to the other modes describedabove. In some embodiments, this mode has keys that are dynamicallygenerated.

Receiver ADV Service Data Format

In some embodiments, data packets that are broadcasted by the secondcommunications radio (also referred to herein as BLE advertisements forembodiments in which BLE radios are used) include a predeterminedformat, an example of that format is provided below for reference:

Byte Number Encryption Length Value Description  0 Open 1 0x12 Length ofAdvertisement Data  1 1 0x16 Service Data Type  2 2 0xFFFC AirfuelAlliance SDO  4 1 0x00 Technology Type, RF-A, Manufacturer Specific  5 10x5X Advertisement Format Version (AFV)  6 Encrypted 2 0xXX SequenceCounter  8 1 0xXX Receiver AD Flags  9 1 0x00 BLE TX power in dBm(Signed) 10 1 0x00 Battery Percentage (Encoded) 11 2 0x0000 Device Powerin mW (Encoded) 13 2 0x0000 Array Voltage in mV (Encoded) 15 2 0x0000Load Voltage in mV (Encoded) 17 2 0x0000 Array Power in mW (Encoded) 192 0x0000 Battery Voltage in mV (Encoded)

In other words, in some embodiments, the data packet and the additionaldata packet(s) provided by the second communications radio includeinformation pertaining to: Length of Advertisement Data, Service DataType, Airfuel Alliance SDO, Technology Type, RF-A, manufacturerspecific, Advertisement Format Version (AFV), Sequence Counter, ReceiverAD Flags, BLE TX power in dBm (Signed), Battery Percentage (Encoded),Device Power in mW (Encoded), Array Voltage in mV (Encoded), LoadVoltage in mV (Encoded), Array Power in mW (Encoded), and/or BatteryVoltage in mV (Encoded). In some embodiments, a first set of the dataincluded in the data packets that are broadcasted by the receivers isencrypted/encoded, while a second set of the data included in the datapackets that are broadcasted by the receivers is not encrypted/encoded.

Additional details regarding the data included with some of the bytes inthe data packets that are broadcasted by the receivers are also providedbelow.

Receiver Advertisement Format Version

The below table illustrates additional structure/information concerningbyte 5 in the example data packets broadcasted by a receiver device thatwere discussed above. This additional structure/information helps toensure a common advertisement messaging structure that supports multipletypes of devices. Using this structure, communicating devices candistinguish the type of device, their supported message formats, andtheir encryption status. This also allows for future modification of themessage structure without breaking backwards compatibility.

Bit 7 6 5 4 3 2 1 0 Desc Protocol Version Encr MF/FF NF/NF+ 0-TX 1-RX

In some embodiments, at least four bits of the common advertisementmessaging structure is allocated to the protocol version. In someembodiments, at least one bit of the common advertisement messagingstructure is allocated to encryption. In some embodiments, at least onebit of the common advertisement messaging structure is allocated toMF/FF data. In some embodiments, at least one bit of the commonadvertisement messaging structure is allocated to NF/NF+ data. In someembodiments, at least one bit of the common advertisement messagingstructure is allocated to information as to whether the data correspondsto the transmitter or receiver.

Receiver AD Flags

The below table illustrates additional structure/information concerningbyte 8 in the example data packets broadcasted by a receiver device thatwere discussed above. The below table shows a set of flags that indicatea receiver's charging status, which helps a transmitter determine thebest charging algorithm for optimal system performance (e.g., a chargingalgorithm that ensures the receiver is receiving an amount of usablepower that is sufficient to provide power or charge to the receiver).

Bit 7 6 5 4 3 2 1 0 Desc 0-1 Byte Charge Status On Battery ChargeConnectable Status Charger Critical Required 1-2 Byte Status

Charge Status

In some embodiments, the example data packets broadcasted by a receiverdevice that were discussed above can include information related to acharge status of the receiver device. The table below details examplesof the different charge statuses that the broadcasted data packets canconvey. These are provided to the transmitter to help it determine thebest charging algorithm (e.g., a charging algorithm that ensures thereceiver is receiving an amount of usable power that is sufficient toprovide power or charge to the receiver).

Bit 6 Bit 5 Bit 4 Description 0 0 0 0 - Not Charging 0 0 1 1 - IncrementRequired 0 1 0 2 - Power Optimal 0 1 1 3 - Decrement Required 1 0 0 4 -Fault 1 0 1 5 - Busy — — — Other Values Reserved

The methods described herein can make use of the charging statusinformation to help improve charging operations. For instance, themethods described herein can include an operation of: in accordance witha determination that broadcasted data packet from awireless-power-receiving device includes information regarding thewireless-power-receiving device's charge status, thewireless-power-transmitting device is then configured to make anadjustment to the transmission of wireless power that is based on thecharging status information (e.g., if the bits 4 through 6 indicate thatthe receiver requires an increment, then the wireless-power-transmittingdevice can adjust the transmission of wireless power by increasing apower level with which the power is being delivered to the receiver.

Receiver Charger Detection

In some embodiments, the a device with which the receivers describedherein are coupled (e.g., an electronic device configured to receiveusable power from the receiver device) can perform charger polling(which can be referred to as receiver charge detection herein) duringwhich an application running on the device can periodically poll (e.g.,once every 1 or 2 minutes) for presence of a wireless-power transmitterin proximity to the receiver. Once the charger is detected (e.g.,because a power transmission signal is received at the receiver), thenthe application running on the device can cause can the receiver tobegin running a new routine or another software program that causes thereceiver to update its broadcasted data packet (e.g., as indicated bythe process 414 shown in FIG. 4 ).

In some embodiments, the receiver charge detection is a receiver singleimage with charger interrupt. In this mode, the device with which thereceiver is coupled can configure a Varray pin as GPIO and interruptlogic HIGH, in accordance with one example technique. The interrupt willbe generated once the receiver is put on the charger. The applicationcan start the new routine or other software program discussed above andcan update the information included in the broadcasted data packets(e.g., as indicated by the process 414 shown in FIG. 4 ).

In some embodiments, the receiver charge detection is a receiver dualimage. In this mode, the charger detection should be part of the devicewith which the receiver is coupled. This can be performed by eitherpolling or interrupt. On charger detection customer image can load thenew routine or other software program discussed above.

Additional Description of Example Embodiments

FIGS. 5A-5C show flow diagrams of a method of transmittingunidirectional communication signals, in accordance with someembodiments. Specifically, FIG. 5A-5C shows a method 500 of securing(502) wireless transmission of power using unidirectional communicationsignals from a wireless-power-receiving device occurs at awireless-power-receiving device (e.g., receiver 120 in FIG. 1A, receiver120 in FIG. 3 , and receiver 404 (equivalent to receiver 120) FIG. 4 ).

In some embodiments, a wireless-power-receiving device receives (504),from a wireless-power-transmitting device (e.g., transmitter 102 in FIG.1A, transmitter 102 in FIG. 2 , and wireless-power transmitting device402 (equivalent to transmitter 102) in FIG. 4 ) that includes a firstcommunications radio, a first wireless-power-transmission signal at awireless-power-receiving device that includes a second communicationsradio.

In some embodiments, in response to the a wireless-power-receivingdevice receiving (506) the first wireless-power-transmission signal(e.g., FIG. 4 shows an arrow 418 that indicates that a WPT Beacon istransmitted from the wireless-power-transmitting device 404):broadcasting (508), via the second communications radio of thewireless-power-receiving device and without establishing acommunications channel between the first and second communicationsradios, a data packet, the data packet including information identifying(i) at least one power requirement of a power source of thewireless-power-receiving device (ii) an amount of power received by thewireless-power-receiving device from the firstwireless-power-transmission signal (e.g., FIG. 4 shows an arrow 406indicating that a BLE advertisement is broadcasted from thewireless-power-receiving device 404).

In some embodiments, after broadcasting the data packet, receiving(510), from the wireless-power-transmitting device, additionalwireless-power-transmission signals at the wireless-power-receivingdevice (e.g., FIG. 4 shows an arrow 408 that indicates that additionalwireless-power-transmission signals have been sent from thewireless-power-transmitting device 402). In some embodiments, thewireless-power-transmitting device transmits each of the additionalwireless-power-transmission signals using a predetermined sequence ofdifferent transmission characteristics (e.g., as indicated in FIG. 4 bythe process block 412).

In some embodiments, in response to the wireless-power-receiving devicereceiving each additional wireless-power transmission signal,broadcasting (512), via the second communications radio of thewireless-power-receiving device and without establishing acommunications channel between the first and second communicationsradios, an additional data packet (e.g., FIG. 4 shows an arrow 420 thatindicates an additional data packet), each respective additional datapacket including information regarding receipt of the additionalwireless-power-transmission signal.

In some embodiments, the wireless-power-transmitting device compares(514) the information regarding receipt of the additionalwireless-power-transmission signals to the predetermined sequence ofdifferent transmission characteristics to determine whether to continuewirelessly transmitting power to the wireless-power-receiving device(e.g., as indicated in FIG. 4 by the process block 412).

Turning next to FIG. 5B and continuing the description of method 500, insome embodiments, the data packet and the additional data packets arebroadcast (516) via a Bluetooth low energy (BLE) communication protocol(e.g., arrows 406 and 420 in FIG. 4 indicate that BLE advertisements arebroadcasted from the wireless-power-receiving device 404).

In some embodiments, the additional data packets include informationthat causes the wireless-power-transmitting device to adjust (518)characteristics of the additional wireless-power-transmission signalsprovided to the wireless-power receiving device (e.g., FIG. 4illustrates that after the transmitter 402 receives the BLEadvertisement, as indicated by arrow 406, the wireless powertransmitting device 402 begins sending additional RF power, as indicatedby arrow 408). In some embodiments, the wireless-power-transmittingdevice (e.g., transmitter 402 in FIG. 4 ) adjusts characteristics of theadditional wireless power transmission signals when the informationspecifies that the wireless-power-transmitting device (i) is notcharging, (ii) is charging but needs more power, (iii) is charging at anoptimal configured rate, (iv) is charging but is receiving too muchpower, and (v) has a fault condition.

In some embodiments, the wireless-power-receiving device is within awireless-power-transmission range of the wireless-power-transmittingdevice when the second communications radio transmits (520) the datapacket (e.g., as indicated by text box 422 in FIG. 4 that states “OnCharger Detection” and after that detection occurs the BLE Advertisementis sent, as indicated by arrow 406 in FIG. 4 ).

In some embodiments, the wireless-power-transmission range is near-fieldtransmission range of less than or equal to 12 inches from thewireless-power-transmitting device (522) (e.g., as indicated by text box424 that states that the “user places receiver on top of transmitter”).In some embodiments, the wireless-power-transmission range is afar-field transmission range of greater than 12 inches from thewireless-power transmission device (524).

In some embodiments, the wireless-power-receiving device is placed (526)within the wireless-power-transmission range before receiving the firstwireless-power-transmission signal at the wireless-power-receivingdevice and while the first communications radio of thewireless-power-transmitting device is not scanning (e.g., as indicatedby text box 424). In some embodiments, the wireless-power-transmittingdevice causes (526) the first communications radio to begin scanning forbroadcasted data packets in response to detecting thewireless-power-receiving device within the wireless-power-transmissionrange (e.g., as indicated by text box 426 in FIG. 4 that states“receiver detected BLE scanning enabled”).

Turning next to FIG. 5C and continuing the description of method 500, insome embodiments, the predetermined sequence of different transmissioncharacteristics is a sequence in which the wireless-power-transmittingdevice sends (528) the additional wireless-power-transmission signals atdifferent points in time by toggling transmissions on and off over agiven period of time (e.g., as indicated in FIG. 4 by the process block412).

In some embodiments, the predetermined sequence of differenttransmission characteristics is a sequence in which thewireless-power-transmitting device transmits (530) each of theadditional wireless-power-transmission signals using different powerlevels (e.g., as indicated in FIG. 4 by the process block 412).

In some embodiments, the second communications radio of thewireless-power-receiving device communicates (532) in a unidirectionalmanner with the first communications radio of thewireless-power-transmitting device and does not receive communicationfrom the wireless-power-transmitting device (e.g., as shown in FIG. 4 ).

In some embodiments, the wireless-power-receiving device broadcasts(534) each of the data packet and the additional data packets at apredetermined time interval (e.g., as shown by text box 410 indicatingthat BLE advertisements are sent every preset period of time). In someembodiments, the predetermined time interval is equal to 100 ms or less(536) (e.g., as shown by text box 410 indicating that BLE advertisementsare sent every 100 ms). In some embodiments, the predetermined timeinterval is adjustable and can be configured to be 50 ms, 100 ms, 200ms, 300 ms, 500 ms, or any value below 300 ms. This allows for quicktransmission of packets, which causes a quicker response in adjustingpower from the wireless-power-transmitting device, Consequently,resulting in better control of the charging characteristics withoutdamaging the battery or other equipment of thewireless-receiving-receiving device.

In some embodiments, the data packet and each respective additional datapacket include information about current charging state, voltage, powerreceived from the wireless-power-transmitting device, and informationindicating whether more or less power is required (538) (e.g., BLEadvertisements 406 and 420 shown in FIG. 4 include this information).

In some embodiments, the data packet and each respective additional datapacket include encrypted data (540) (e.g., BLE advertisements 406 and420 shown in FIG. 4 can include encrypted data).

In some embodiments, the wireless-power-receiving device includes awireless-power-receiving circuit with power-harvesting circuitry and amemory of approximately 32 KBs (542) (e.g., FIG. 3 showing components ofan example RF receiver), and the memory stores instructions that causethe wireless-power-receiving device to perform the instructions of thediscussed unidirectional charging process. In some embodiments, theseinstructions occupy approximately 5 KBs or less of the memory (542). Ascompared to other systems, an instruction size of 5 KBs represents asignificant reduction in the program space, thereby freeing up memoryspace for other purposes on the receiver side (e.g., receiver 120 inFIG. 3 ). In this way, the techniques described herein allow thereceiver chip to operate more efficiently (e.g., receiver 120 in FIG. 3).

In some embodiments, data packet and the additional data packet alsoinclude information regarding a charge status of the power sourceselected from a group consisting of: the power source (i) is notcharging, (ii) is charging but needs more power, (iii) is charging at anoptimal configured rate, (iv) is charging but is receiving too muchpower, and (v) has a fault condition (544) (e.g., BLE advertisements 406and 420 in FIG. 4 include this information).

In some embodiments, a wireless-power-receiving device that includes awireless-power-receiving circuit having a memory storing instructionsfor securely transmitting wireless power using unidirectionalcommunication signals from a wireless-power-receiving device, theinstructions causing performance of any of the above discussed features.In some embodiments, a system comprises a receiver and a transmitter,wherein the receiver and transmitter are configured to performoperations to allow for execution of any of the above-discussedfeatures. A non-transitory computer-readable storage medium includinginstructions that, when executed by one or more processors of awireless-power-receiving device, cause the one or more processors toperform or cause performance of any of the above discussed features. Awireless-power-receiving device comprising means for causing performanceof any of the above-discussed features.

Although some of various drawings illustrate a number of logical stagesin a particular order, stages which are not order dependent may bereordered and other stages may be combined or broken out. While somereordering or other groupings are specifically mentioned, others will beobvious to those of ordinary skill in the art, so the ordering andgroupings presented herein are not an exhaustive list of alternatives.Moreover, it should be recognized that the stages could be implementedin hardware, firmware, software, or any combination thereof.

The preceding description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the embodimentsdescribed herein and variations thereof. Various modifications to theseembodiments will be readily apparent to those skilled in the art, andthe generic principles defined herein may be applied to otherembodiments without departing from the spirit or scope of the subjectmatter disclosed herein. Thus, the present disclosure is not intended tobe limited to the embodiments shown herein but is to be accorded thewidest scope consistent with the following claims and the principles andnovel features disclosed herein.

Features of this disclosure can be implemented in, using, or with theassistance of a computer program product, such as a storage medium(media) or computer readable storage medium (media) having instructionsstored thereon/in which can be used to program a processing system toperform any of the features presented herein. The storage medium (e.g.,memory 206, 256) can include, but is not limited to, high-speed randomaccess memory, such as DRAM, SRAM, DDR RAM or other random access solidstate memory devices, and may include non-volatile memory, such as oneor more magnetic disk storage devices, optical disk storage devices,flash memory devices, or other non-volatile solid state storage devices.Memory optionally includes one or more storage devices remotely locatedfrom the CPU(s) (e.g., processor(s)). Memory, or alternatively thenon-volatile memory device(s) within the memory, comprises anon-transitory computer readable storage medium.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the claims. Asused in the description of the embodiments and the appended claims, thesingular forms “a,” “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willalso be understood that the term “and/or” as used herein refers to andencompasses any and all possible combinations of one or more of theassociated listed items. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof.

As used herein, the term “if” may be construed to mean “when” or “upon”or “in response to determining” or “in accordance with a determination”or “in response to detecting,” that a stated condition precedent istrue, depending on the context. Similarly, the phrase “if it isdetermined [that a stated condition precedent is true]” or “if [a statedcondition precedent is true]” or “when [a stated condition precedent istrue]” may be construed to mean “upon determining” or “in response todetermining” or “in accordance with a determination” or “upon detecting”or “in response to detecting” that the stated condition precedent istrue, depending on the context.

The foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. However, theillustrative discussions above are not intended to be exhaustive or tolimit the scope of the claims to the precise forms disclosed. Manymodifications and variations are possible in view of the aboveteachings. The embodiments were chosen in order to best explain theprinciples underlying the claims and their practical applications, tothereby enable others skilled in the art to best use the embodimentswith various modifications as are suited to the particular usescontemplated.

1. (canceled)
 2. A method of secure wireless transmission of power usingunidirectional communication signals from a wireless-power-receivingdevice, comprising: receiving, from a wireless-power-transmitting devicethat includes a first communications radio, a firstwireless-power-transmission signal at a wireless-power-receiving devicethat includes a second communications radio; in response to receivingthe first wireless-power-transmission signal: broadcasting, via thesecond communications radio of the wireless-power-receiving device andwithout establishing a communications channel between the first andsecond communications radios, a data packet that includes informationidentifying (i) at least one power requirement of a power source of thewireless-power-receiving device (ii) an amount of power received by thewireless-power-receiving device from the firstwireless-power-transmission signal.
 3. The method of claim 1, including:after broadcasting the data packet, receiving, from thewireless-power-transmitting device, additionalwireless-power-transmission signals at the wireless-power-receivingdevice, wherein information in the additionalwireless-power-transmission signals is based on the data packet.
 4. Themethod of claim 1, wherein the data packet is broadcast via a low-energycommunication protocol.
 5. The method of claim 1, wherein: thewireless-power-transmitting device that includes the firstcommunications radio is also configured to send a secondwireless-power-transmission signal to another wireless-power-receivingdevice that includes a third communications radio; the otherwireless-power-receiving device is configured to, in response toreceiving the second wireless-power-transmission signal, broadcast, viathe third communications radio of the other wireless-power-receivingdevice and without establishing a communications channel between thefirst and third communications radios, another data packet, the otherdata packet including information identifying (i) at least one powerrequirement of a power source of the other wireless-power-receivingdevice (ii) an amount of power received by the otherwireless-power-receiving device from the secondwireless-power-transmission signal.
 6. The method of claim 5, whereinthe wireless-power-receiving device and the otherwireless-power-receiving device receive power from thewireless-power-transmitting device during at least one overlappingperiod of time.
 7. The method of claim 5, wherein thewireless-power-receiving device is a different type of electronic devicethan the other wireless-power-receiving device.
 8. The method of claim1, wherein the wireless-power-receiving device is within awireless-power-transmission range of the wireless-power-transmittingdevice when the second communications radio transmits the data packet.9. The method of claim 8, wherein the wireless-power-transmission rangeis a near-field transmission range of less than or equal to 12 inchesfrom the wireless-power-transmitting device.
 10. The method of claim 8,wherein the wireless-power-transmission range is a far-fieldtransmission range of greater than 12 inches from thewireless-power-transmitting device.
 11. The method of claim 1, whereinthe wireless-power-transmitting device includes a charging pad that thewireless-power-receiving device rests on.
 12. The method of claim 11,wherein the wireless-power-transmitting device includes a plurality ofantennas, wherein respective antennas of the plurality of antennas areconfigured to be activated based on a determined location of thewireless-power-receiving device on the charging pad.
 13. The method ofclaim 1, wherein the second communications radio of thewireless-power-receiving device communicates in a unidirectional mannerwith the first communications radio of the wireless-power-transmittingdevice and does not receive any communication signals from the firstcommunications radio of the wireless-power-transmitting device.
 14. Themethod of claim 1, wherein the data packet includes encrypted data. 15.The method of claim 1, wherein the data packet also includes informationregarding a charge status of a power source for thewireless-power-receiving device, the information regarding the chargestatus of the power source including an indication of one or more of:the power source (i) is not charging, (ii) is charging but needs morepower, (iii) is charging at an optimal configured rate, (iv) is chargingbut is receiving too much power, and (v) has a fault condition.
 16. Themethod of claim 1, wherein the wireless-power-receiving devicebroadcasts the data packet a predetermined time interval beforetransmitting another data packet.
 17. A wireless-power-receiving device,comprising: a power source configured to provide usable power to thewireless-power-receiving device; a second communications radioconfigured to: receive, from a wireless-power-transmitting device thatincludes a first communications radio, a firstwireless-power-transmission signal at a wireless-power-receiving devicethat includes a second communications radio; in response to receivingthe first wireless-power-transmission signal: broadcast, via the secondcommunications radio of the wireless-power-receiving device and withoutestablishing a communications channel between the first and secondcommunications radios, a data packet, the data packet includinginformation identifying (i) at least one power requirement of a powersource of the wireless-power-receiving device (ii) an amount of powerreceived by the wireless-power-receiving device from the firstwireless-power-transmission signal.
 18. A non-transitorycomputer-readable storage medium including instructions that, whenexecuted by one or more processors of a wireless-power-receiving device,cause the wireless-power-receiving device to: receive, from awireless-power-transmitting device that includes a first communicationsradio, a first wireless-power-transmission signal at awireless-power-receiving device that includes a second communicationsradio; in response to receiving the first wireless-power-transmissionsignal: broadcast, via the second communications radio of thewireless-power-receiving device and without establishing acommunications channel between the first and second communicationsradios, a data packet, the data packet including information identifying(i) at least one power requirement of a power source of thewireless-power-receiving device (ii) an amount of power received by thewireless-power-receiving device from the firstwireless-power-transmission signal.